@article{oai:dmu.repo.nii.ac.jp:00001492,
 author = {Kobori, Yoshitomo and Okada, Hiroshi and Niederberger, Craig},
 issue = {2},
 journal = {Dokkyo Journal of Medical Sciences},
 month = {Jul},
 note = {Purpose：Reactive oxygen species have been suggested as a major contributing factor to cryodamage of the spermatozoa. Accordingly, antioxidant supplementation has been used to yield significantly improved quality of frozen sperm post-thaw. We sought to investigate outcomes with a combination of antioxidants
catalase and N-acetylcysteine respectively. 

Methods：The cryomedium supplemented with 200U/ml catalase, 5 mM N-acetylcysteine and their combination was used. Semen samples were collected from normozoospermic men （n＝20）and aliquots frozen in each dose of antioxidant tested. Post-thaw semen analysis by computer aided sperm analysis was performed. In addition, sperm viability （Eosin-Y staining） and sperm DNA fragmentation（TUNEL assay）were quantitated. 

Results：Combined catalase and N-acetylcysteine supplementation during cryopreservation resulted in significantly improved post-thaw recovery of total motility（from 39.4±15.8％ to 49.2±16.1％） and percentage of sperm vitality （from 46.2±13.3％ to 53.2±11.8％）（mean±SD, p＜0.05）. Catalase improved post-thaw DNA integrity analysis for doublestranded breaks using TUNEL assay. 

Conclusions：These results indicated that the combination of intracellular and extracellular antioxidants resulted in the pronounced effect in improving post-thaw quality of human spermatozoa.},
 pages = {135--140},
 title = {Supplementation of Cryomedium with Catalase and N-acetylcysteine Improves Human Sperm Post-thaw Motility and DNA Integrity},
 volume = {44},
 year = {2017}
}